Red hair can appear as light red, or "strawberry blonde" ("blond" for males), as "carrot top" orange, as ginger, copper, or as medium to dark "auburn" red, all attributable to relatively high levels of the reddish pigment pheomelanin.
Light eyes (gray, blue, and green), light skin, and freckles are associated with the recessive red-hair gene (melanocortin 1 receptor, or MC1R, found on the 16th of the 23 human chromosome pairs), which has existed for only about 50,000 years according to Jonathan Rees of the University of Edinburgh in Scotland, who identified the red-hair gene in 1995.
Increased Sensitivity to Sunlight and Pain
Red-haired people tend to have increased sensitivity to UV radiation, allowing adequate Vitamin D generation in low sunlight climates, but increased susceptibility to skin cancer in high sunlight areas. Fair skin increases a person's ability to retain heat, which adds advantage in low sunlight climates.
The hormone responsible for red hair, pheomelanin, also stimulates a brain receptor for pain, specifically to thermal cold and heat-related pain (Liem, Edwin B., et al. "Increased Sensitivity to Thermal Pain and Reduced Subcutaneous Lidocaine Efficacy in Redheads." NIH Public Access Author Manuscript. Anesthesiology, March 2005).
Origins of Red Hair
Only 1 to 2 percent of the human population has red hair, many of whom come from Western or Northern European descent, although red hair can be found around the globe ("Red Alert!" The Washington Post, March 19, 2002).
- Scotland has the highest percentage of people with red hair (13 percent of the population has red hair and 40 percent carries the gene.)
- Ireland has the second highest percentage of red-haired people (10 percent have red hair and 46 percent carry the gene.)
- Wales has the third highest percentage (nearly 10 percent of the population have red hair.)
According to some geneticists, red hair is representative of the British Isles' most ancient lineages, such as the Picts who were described as large, red-haired people. Some surnames reflect a clan or family's common hereditary coloring, such as the Irish Flanary ("red eyebrow"), Flynn ("bright red"), Flanagan ("red, ruddy"), and Reid ("red-haired, ruddy complexion").
Historically, Greek writers have described certain areas as having large red-headed populations, such as the Udmurt people of the Volga, now known as Russia, and the Tocharians of northwestern China.
People with the rarest hair color and associated characteristics can be found around the world, especially in the cold climates such as the northwestern areas of Europe where redheads appear to have emerged some 50,000 years ago. Redheads the world over share the experience of having a relatively uncommon trait.
Sara McGrath - Sara is a veteran homeschool mom of three, Usborne consultant, and the author of Unschooling: A Lifestyle of Learning.
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